AMD Zen Details Finally Unveiled

At this year’s Hot Chips, AMD has finally lifted the veil on its latest CPU architecture called Zen. Through snippets of news that the chip maker has been teasing the public with basic info like the fact that Zen will have 40% more Instructions Per Clock (IPC) over the Excavator architecture. But now, more has been revealed.

According to AMD, Zen CPUs will span the entire range from fanless mobile PCs to servers. AMD is planning to release the first Zen CPUs next year, beginning with high-performance desktops and enterprise servers, before moving on to mobile PCs and embedded applications.

Designed from the ground up based on a new 14nm FinFET process, AMD Zen is the first AMD microarchitecture that will feature Simultaneous Multi-Threading, which is the equivalent of Intel’s Hyper-Threading. In essence, each core in a Zen CPU will be able to run two threads at the same time. Each core is also able to decode four instructions per cycle, thanks to a new micro-op cache system, which results in greater single-threaded performance.

For the upcoming Summit Ridge Zen CPUs, they will come specifically with 8MB shared L3 cache and a large unified L2 cache. No further specifications have been announced. As for the new upcoming platform, AMD has prepared a successor to the AM3 and simply named it “AM4”. AM4 will support DDR4 memory, PCI-E Gen 3.0, and new generation I/O standards.

Prior to Hot Chips, AMD did a performance comparison between two systems, one featuring a Zen CPU and the other an Intel Broadwell-E processor. Both chips had similar specs: eight cores and sixteen threads, with all cores set to operate at a clockspeed of 3 GHz. The two system were pitted against one another in a Blender (an open source rendering engine) rendering test. AMD’s Zen CPU edged out its Intel counterpart by about one second, completing the chosen workload in 48.07 seconds. Granted, the public were not given the full specifications of both system, so the credibility of the result should be taken with a pinch of salt.